Endoscopic insertion aid, endoscopic system, and method of inserting insertion portion of endoscope into body cavity by use of endoscopic insertion aid

ABSTRACT

An endoscopic insertion aid includes a tube member, a pipeline and a plurality of balloons. The tube member allows an insertion section of an endoscope to be inserted therethrough, and guides the longitudinal movement of the insertion section. The pipeline is provided in the tube member, and communicates with a supply/discharge unit to supply a fluid to or discharge the fluid from the distal end of the tube member. The balloons are disposed on the outer periphery of the distal end of the tube member longitudinally along the tube member, communicate with the pipeline, and inflate/deflate in accordance with the supply/discharge of the fluid via the pipeline. The balloon disposed on the distal side of the tube member is inflated to have an outside diameter larger than that of the balloon disposed closer to the proximal side than the balloon disposed on the distal side when the balloons are inflated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. application Ser. No. 11/779,601filed Jul. 18, 2007 and is based upon and claims the benefit of priorityfrom prior Japanese Patent Application No. 2006-210066, filed Aug. 1,2006, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an endoscopic insertion aid for facilitatinginsertion by aiding in the insertion of an insertion section of anendoscope into a region such as the large intestine where insertion isdifficult, an endoscopic system, and a method of inserting the insertionsection of the endoscope into a body cavity by use of the endoscopicinsertion aid.

2. Description of the Related Art

For example, an endoscopic insertion aid having a plurality of balloonsat its distal end is disclosed in Jpn. Pat. Appln. KOKAI Publication No.10-155733. In this endoscopic insertion aid, the inner wall of a bodycavity is expanded outward by the balloons to pull the aid to a handside so that the aid is fixed to the inner wall of the body cavity.Then, for example, bent parts or twisted parts of the intestinal wallbecome substantially straight, thereby permitting the improvement of theinsertability of an insertion section.

BRIEF SUMMARY OF THE INVENTION

An endoscopic insertion aid according to this invention includes: a tubemember, a pipeline and a plurality of balloons. The tube member allowsan insertion section of an endoscope to be inserted therethrough, andguides the longitudinal movement of the insertion section. The pipelineis provided in the tube member, and communicates with a supply/dischargeunit to supply a fluid to the distal end of the tube member or dischargethe fluid from the distal end of the tube member. The plurality ofballoons are disposed on the outer periphery of the distal end of thetube member longitudinally along the tube member, communicate with thepipeline, and inflate/deflate in accordance with the supply/discharge ofthe fluid via the pipeline. The balloon disposed on the distal side ofthe tube member is inflated to have an outside diameter larger than thatof the balloon disposed closer to the proximal side of the tube memberthan the balloon disposed on the distal side when the plurality ofballoons are inflated.

An endoscopic insertion aid according to this invention includes: a tubemember, a pipeline, a plurality of balloons and regulating means. Thetube member allows an insertion section of an endoscope to be insertedtherethrough, and guides the longitudinal movement of the insertionsection. The pipeline is provided in the tube member, and communicateswith a supply/discharge unit to supply a fluid to the distal end of thetube member or discharge the fluid from the distal end of the tubemember. The plurality of balloons are disposed at the distal end of thetube member longitudinally along the tube member, communicate with thepipeline, and inflate/deflate in accordance with the supply/discharge ofthe fluid via the pipeline. The regulating means operates so that theballoon disposed on the distal side of the tube member is inflated tohave an outside diameter larger than that of the balloon disposed closerto the proximal side of the tube member than the balloon disposed on thedistal side when the plurality of balloons are inflated.

Advantages of the invention will be set forth in the description whichfollows, and in part will be obvious from the description, or may belearned by practice of the invention. Advantages of the invention may berealized and obtained by means of the instrumentalities and combinationsparticularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a schematic diagram showing an endoscopic system according toa first embodiment of the present invention;

FIG. 2 is a schematic longitudinal sectional view showing an overtube inthe endoscopic system according to the first embodiment;

FIGS. 3A to 3D are schematic diagrams showing a procedure for insertingan insertion section of an endoscope into the large intestine by use ofthe endoscopic system according to the first embodiment;

FIGS. 4A to 4D are schematic diagrams showing a procedure for insertingthe insertion section of the endoscope into the large intestine by useof the endoscopic system according to the first embodiment;

FIG. 5 is a schematic longitudinal sectional view showing an overtube inan endoscopic system according to a second embodiment of the presentinvention;

FIG. 6 is a schematic longitudinal sectional view showing an overtube inan endoscopic system according to a third embodiment of the presentinvention;

FIG. 7 is a schematic longitudinal sectional view showing the distal endof the overtube in the endoscopic system according to the thirdembodiment of the present invention;

FIG. 8A is a schematic longitudinal sectional view showing the distalend of an overtube in an endoscopic system according to a fourthembodiment of the present invention;

FIG. 8B is a schematic transverse sectional view along the 8B-8B line inFIG. 8A; and

FIG. 8C is a schematic longitudinal sectional view showing the distalend of the overtube in the endoscopic system according to the fourthembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A best mode of carrying out this invention will hereinafter be describedwith reference to the drawings.

A first embodiment will be described using FIGS. 1 to 4D.

As shown in FIG. 1, an endoscopic system 10 includes an endoscope 12, anovertube (insertion aid) 14, a light source unit 16, a video processor18, a monitor 20, and a balloon control unit (supply/discharge unit) 22.

The endoscope 12 includes an elongate insertion section 32, and anoperation section 34 provided at the proximal end of the insertionsection 32, and a universal cord 36 extending from the operation section34. The light source unit 16 is optically connected to a connector 36 aat the end of the universal cord 36. Light emitted from the light sourceunit 16 exits from the distal end of the insertion section 32 via theuniversal cord 36, the operation section 34 and the insertion section32. The video processor 18 is further electrically connected to aconnector 36 b at the end of the universal cord 36 extending in additionto the above-mentioned connector 36 a. The monitor 20 is electricallyconnected to the video processor 18 via a cable 20 a. Thus, when anoptical image of a specimen is picked up by a solid-state image sensingdevice such as a CCD described later, its signal is processed by thevideo processor 18, and the image of the specimen picked up is displayedon the monitor 20.

The insertion section 32 includes a rigid distal portion 42, a bendingportion 44 capable of vertically and horizontally bending, and a longand flexible tube portion 46.

The rigid distal portion 42 is disposed at a most distal position of theinsertion section 32. The rigid distal portion 42 is provided with aforceps opening communicating with an illumination optical system, anobservation optical system such as the solid-state image sensing device,and a treatment tool insertion channel, and also provided with a nozzlefor supplying air into a body cavity and water to an observation lens(neither the forceps opening nor the nozzle is shown). The treatmenttool insertion channel communicates with a treatment tool insertion hole(not shown) of the operation section 34.

The distal end of the bending portion 44 is coupled to the proximal endof the rigid distal portion 42. The distal end of the flexible tubeportion 46 is coupled to the proximal end of the bending portion 44. Thedistal end of the operation section 34 is coupled to the proximal end ofthe flexible tube portion 46. That is, the distal end of the operationsection 34 is coupled to the proximal end of the insertion section 32.

The operation section 34 is provided with a remote switch 52 for theremote control of the video processor 18, etc., and a bending operationknob 54 rotated by an operator. When the bending operation knob 54 isoperated, the above-mentioned bending portion 44 of the insertionsection 32 curves in directions to deviate from the longitudinal axis ofthe flexible tube portion 46, for example, vertically and horizontally.

As shown in FIG. 2, the overtube 14 includes a main body (tube member)62 disposed to cover the outer periphery of the insertion section 32 ofthe endoscope 12, a grip 64 provided at the proximal end of the mainbody 62, and first to third balloons 66 a, 66 b and 66 c provided on theouter peripheral surface of the distal end of the main body 62. In themain body 62 and the grip 64, a balloon communication pipeline 68 isformed which communicates with the first to third balloons 66 a, 66 band 66 c. The distal end of the balloon communication pipeline 68communicates with the first to third balloons 66 a, 66 b and 66 c. Theproximal end of the balloon communication pipeline 68 communicates witha connector 64 a provided in the grip 64.

A connection pipeline 70 is disposed between the overtube 14 and theballoon control unit 22. Connectors 70 a and 70 b are provided at oneend and the other end of the connection pipeline 70, respectively. Theconnector 70 a at one end of the connection pipeline 70 is connected tothe connector 64 a of the grip 64. The connector 70 b at the other endof the connection pipeline 70 is connected to a connector 22 a of theballoon control unit 22.

The balloon control unit 22 includes a pump 72 capable ofsupplying/discharging (sucking) a gas, a control circuit 74 forcontrolling the pump 72, and a remote controller 76 electricallyconnected to the control circuit 74 via a connection cable 76 a. Thisremote controller 76 is provided with a stop button 78 a, apressurization button 78 b and a decompression button 78 c. When thestop button 78 a is depressed, its signal is input to the controlcircuit 74. Then, the control circuit 74 stops the operation of the pump72. When the pressurization button 78 b is depressed, its signal isinput to the control circuit 74. Then, the control circuit 74 operatesthe pump 72 so that the gas is supplied from the connection pipeline 70to the balloon communication pipeline 68 of the overtube 14. When thedecompression button 78 c is depressed, its signal is input to thecontrol circuit 74. Then, the control circuit 74 operates the pump 72 sothat the gas is discharged from the connection pipeline 70 and theballoon communication pipeline 68 of the overtube 14.

As shown in FIGS. 1 and 2, for example, the three first to thirdballoons 66 a, 66 b and 66 c are disposed at the distal end of theovertube 14. The balloons 66 a, 66 b and 66 c are formed of, forexample, silicone rubber, latex rubber, or an elastic elastomer. Theballoons 66 a, 66 b and 66 c communicate with each other through theballoon communication pipeline 68 provided in the main body 62. Further,the outside diameter of the first balloon 66 a on the most distal sidewhen inflated is formed to be greater than the outside diameter of theadjacent second balloon 66 b when inflated. Moreover, the outsidediameter of the third balloon 66 c adjacent to the second balloon 66 bis formed to be smaller than that of the second balloon 66 b when thesecond and third balloons 66 b and 66 c are inflated.

It is to be noted that the balloons 66 a, 66 b and 66 c are formed of,for example, one cylindrical member. The distal end and proximal end ofthis cylindrical member are fixed by being wound and bound with, forexample, threads 80 (see FIG. 7). Then, the cylindrical member is woundand bound with the threads 80 at appropriate two places so that thefirst to third balloons 66 a, 66 b and 66 c are formed. Further, anadhesive is applied to the parts wound with the threads 80 for fixture.Thus, the first to third balloons 66 a, 66 b and 66 c are formed.

Next, the function of the endoscopic system 10 according to thisembodiment will be described using FIGS. 3A to 4D.

The insertion section 32 of the endoscope 12 is per anum inserted intothe large intestine C shown in FIG. 3A, and the main body 62 of theovertube 14 is inserted.

As shown in FIG. 3B, the pressurization button 78 b of the remotecontroller 76 is depressed. A signal is input from the remote controller76 to the control circuit 74 via the connection cable 76 a. The controlcircuit 74 operates the pump 72 while controlling the pump 72. Then, theballoons 66 a, 66 b and 66 c of the overtube 14 are inflated so that theintestinal wall is expanded outward by the balloons 66 a, 66 b and 66 c.At this point, for example, the pump 72 is controlled by the controlcircuit 74 to adjust the velocity and amount of a fluid (gas), therebyslowly inflating the balloons 66 a, 66 b and 66 c. Thus, the balloons 66a, 66 b and 66 c slowly expand the intestinal wall outward. Further, theposition of the overtube 14 is held to the large intestine C byfrictional force between the balloons 66 a, 66 b and 66 c and the innerwall of the intestine.

It is to be noted that the pressurization of the balloons 66 a, 66 b and66 c is automatically stopped when specified pressure is reached.Alternatively, the stop button 78 a is depressed and its signal is inputto the control circuit 74 before the specified pressure is reached. Thecontrol circuit 74 stops the operation of the pump 72.

When the balloons 66 a, 66 b and 66 c of the overtube 14 are inflated asshown in FIG. 3B, the intestinal wall is expanded outward so that thedistal side of the first balloon 66 a is also expanded. Thus, as shownin FIG. 3C, the insertion section 32 of the endoscope 12 is moved to theinner side of the large intestine C while the position of the overtube14 is being held. At this point, the bending portion 44 of the insertionsection 32 is caused to further project forward from the distal end ofthe main body 62 of the overtube 14.

Then, the bending operation knob 54 of the operation section 34 isoperated to curve the bending portion 44 of the insertion section 32, asshown in FIG. 3D. Thus, the large intestine C deforms in an S-shape.Therefore, the large intestine C is held so that it is substantiallycaught between the bending portion 44 of the insertion section 32 of theendoscope 12 and the rigid distal portion 42.

The decompression button 78 c of the remote controller 76 is operated tooperate the pump 72, and the balloons 66 a, 66 b and 66 c of theovertube 14 are deflated, as shown in FIG. 4A. At this point, the pump72 is controlled by the control circuit 74 to discharge the gas from theballoons 66 a, 66 b and 66 c as fast as possible. Then, it is possibleto quickly move on to the next operation.

As shown in FIG. 4B, the overtube 14 is moved to the inner side alongthe insertion section 32 of the endoscope 12.

As shown in FIG. 4C, the balloons 66 a, 66 b and 66 c of the overtube 14are inflated to expand the wall of the large intestine C. In this caseas well, the balloons 66 a, 66 b and 66 c are slowly inflated. Then, theposition of the overtube 14 is fixed by the balloons 66 a, 66 b and 66c.

As shown in FIG. 4D, the bending operation knob 54 of the operationsection 34 of the endoscope 12 is operated to make the curved bendingportion 44 of the insertion section 32 straight. That is, the holding ofthe large intestine C by the bending portion 44 of the insertion section32 and the rigid distal portion 42 is released. Further, the overtube 14and the insertion section 32 of the endoscope 12 are pulled together sothat their relative movement is prevented. Then, using the balloons 66a, 66 b and 66 c in which the diameter is larger on the distal side andsmaller on the proximal side, the large intestine C is pushed out to thehand side (anal side) by the proximal part of the third balloon 66 c. Inthe same manner, the large intestine C is pushed out to the hand side bythe proximal part of the second balloon 66 b. Further, the largeintestine C is pushed out to the hand side by the proximal part of thethird balloon 66 c. Then, the folds of the inner wall of the largeintestine C are hooked between the first balloon 66 a and the secondballoon 66 b, between the second balloon 66 b and the third balloon 66 cand by the proximal part of the third balloon 66 c. Therefore, when theovertube 14 and the insertion section 32 of the endoscope 12 are pulledtogether, the large intestine C is pulled to the hand side andefficiently folded (shortened) because the folds of the large intestineC are hooked by the balloons 66 a, 66 b and 66 c.

Furthermore, as shown in FIG. 3C, the insertion section 32 of theendoscope 12 is inserted into the inner side with respect to theovertube 14. Subsequently, similar operation is carried out to insertthe distal end of the insertion section 32 into the inner side of thelarge intestine C.

As described above, the following effects can be obtained according tothis embodiment.

The plurality of balloons 66 a, 66 b and 66 c are provided at the distalend of the overtube 14. Moreover, the diameter of the first balloon 66 ais larger than the diameter of the second balloon 66 b, and the diameterof the second balloon 66 b is larger than the diameter of the thirdballoon 66 c. Thus, the effect of hooking the inner wall of the largeintestine C with the balloons 66 a, 66 b and 66 c can be increased whenthe large intestine C is folded onto the anal side. Further, the area ofcontact with the intestinal wall in folding the large intestine C can belarge. Thus, the force of fixing the balloons 66 a, 66 b and 66 c to thewall of the large intestine C can be increased.

In addition, while the use of the three balloons 66 a, 66 b and 66 c hasbeen described in this embodiment, for example, two or four balloons mayalso be used, and the suitable number of balloons is selected.

Next, a second embodiment will be described using FIG. 5. Thisembodiment is a modification of the first embodiment, so that the samesigns are assigned to the same members as those described in the firstembodiment, and these members are not described in detail.

First to third balloons 66 a, 66 b and 66 c are formed into, forexample, separate members, but are formed of the same material at aboutthe same thickness.

As shown in FIG. 5, balloon communication holes 68 a, 68 b and 68 c ofthe balloons 66 a, 66 b and 66 c communicating with a ballooncommunication pipeline 68 have cross-sectional areas different from eachother. The cross-sectional area a of the first balloon communicationhole 68 a providing communication between the first balloon 66 a and theballoon communication pipeline 68 is formed to be the largest. Thecross-sectional area β of the second balloon communication hole 68 bproviding communication between the second balloon 66 b and the ballooncommunication pipeline 68 is formed to be smaller than that of the firstballoon communication hole 68 a. The cross-sectional area γ of the thirdballoon communication hole 68 c providing communication between thethird balloon 66 c and the balloon communication pipeline 68 is formedto be smaller than that of the second balloon communication hole 68 b.

Thus, when a gas is introduced through the balloon communicationpipeline 68, the amount of gas flowing from the second ballooncommunication hole 68 b into the second balloon 66 b is greater than theamount of gas flowing from the third balloon communication hole 68 cinto the third balloon 66 c. Moreover, the amount of gas flowing fromthe first balloon communication hole 68 a into the first balloon 66 a isgreater than the amount of gas flowing from the second ballooncommunication hole 68 b into the second balloon 66 b.

Therefore, the times for inflating the first to third balloons 66 a, 66b and 66 c can be about the same. Then, it is possible to prevent, forexample, any one of the first to third balloons 66 a, 66 b and 66 c frombeing in an overpressurized state or a low pressure state.

Furthermore, the inflation amounts of the balloons 66 a, 66 b and 66 ccan be regulated by the cross-sectional areas α, β and γ of the ballooncommunication holes 68 a, 68 b and 68 c. That is, the relationshipsbetween the cross-sectional areas α, β and γ of the first to thirdballoon communication holes 68 a, 68 b and 68 c serve as means forregulating the inflation amounts of the balloons 66 a, 66 b and 66 c sothat one supply of gas causes the first balloon 66 a to be inflated tothe largest outside diameter, the second balloon 66 b to be inflated tothe second largest outside diameter, and the third balloon 66 c to beinflated to the third largest outside diameter.

Next, a third embodiment will be described using FIGS. 6 and 7. Thisembodiment is a modification of the first embodiment, so that the samesigns are assigned to the same members as those described in the firstembodiment, and these members are not described in detail.

FIG. 7 shows first to third balloons 66 a, 66 b and 66 c in a magnifiedmanner so that an overtube 14 shown in FIG. 6 is rotated 90 degreesaround the axis of a main body 62.

As shown in FIG. 7, the length L₁ from the distal end to proximal end ofthe first balloon 66 a is formed to be larger than the length L₂ fromthe distal end to proximal end of the second balloon 66 b. Further, thelength L₂ from the distal end to proximal end of the second balloon 66 bis formed to be larger than the length L₃ from the distal end toproximal end of the third balloon 66 c.

The length L₁ from the distal end to proximal end of the first balloon66 a is larger than the length L₂ from the distal end to proximal end ofthe second balloon 66 b, such that the space in the first balloon 66 acan be larger. Thus, a greater amount of fluid can be made to flow intothe first balloon 66 a than into the second balloon 66 b. Then, theoutside diameter of the first balloon 66 a on the distal side can belarger than that of the second balloon 66 b on the proximal side. Thesame applies to the relationship between the second balloon 66 b and thethird balloon 66 c.

Thus, the inflation amounts of the balloons 66 a, 66 b and 66 c can beregulated by the relationships between the lengths L₁, L₂ and L₃. Thatis, the relationships between the lengths L₁, L₂ and L₃ of the first tothird balloons 66 a, 66 b and 66 c serve as means for regulating theinflation amounts of the balloons 66 a, 66 b and 66 c so that one supplyof gas causes the first balloon 66 a to be inflated to the largestoutside diameter, the second balloon 66 b to be inflated to the secondlargest outside diameter, and the third balloon 66 c to be inflated tothe third largest outside diameter.

Furthermore, the first to third balloons 66 a, 66 b and 66 c are formedof the same material but are different from each other in thickness. Thethickness t₁ of the first balloon 66 a is formed to be smaller than thethickness t₂ of the second balloon 66 b. The thickness t₂ of the secondballoon 66 b is formed to be smaller than the thickness t₃ of the thirdballoon 66 c.

Therefore, the times for inflating the first to third balloons 66 a, 66b and 66 c can be about the same. Then, it is possible to prevent, forexample, any one of the first to third balloons 66 a, 66 b and 66 c frombeing in an overpressurized state or a low pressure state.

The first to third balloons 66 a, 66 b and 66 c are formed of the samematerial, and the thickness t₁ of the first balloon 66 a is formed to besmaller than the thickness t₂ of the second balloon 66 b, and thethickness t₂ of the second balloon 66 b is formed to be smaller than thethickness t₃ of the third balloon 66 c. Thus, the inflation amounts ofthe balloons 66 a, 66 b and 66 c can be regulated by the relationshipsbetween the thicknesses t₁, t₂ and t₃. That is, the relationshipsbetween the thicknesses t₁, t₂ and t₃ of the first to third balloons 66a, 66 b and 66 c serve as means for regulating the inflation amounts ofthe balloons 66 a, 66 b and 66 c so that one supply of gas causes thefirst balloon 66 a to be inflated to the largest outside diameter, thesecond balloon 66 b to be inflated to the second largest outsidediameter, and the third balloon 66 c to be inflated to the third largestoutside diameter.

In addition, the same material is used and thickness is varied in thefirst to third balloons 66 a, 66 b and 66 c so that their inflationtimes may be substantially equal to each other in this embodimentdescribed above. However, the inflation times of the balloons 66 a, 66 band 66 c can also be made substantially equal to each other by settingthese balloons at a substantially uniform thickness but using materialsof different expansion rates (the first balloon 66 a has the highestexpansion rate and the third balloon 66 c has the lowest expansionrate). In this case, the cross-sectional areas of the first to thirdballoon communication holes 68 a, 68 b and 68 c shown in FIG. 6 may bethe same or different from each other. The cross-sectional areas areproperly set in relation to the thickness and the material.

Furthermore, the first to third balloons 66 a, 66 b and 66 c can also beformed of one cylindrical member. This cylindrical member is formed sothat the thickness becomes linearly greater from the distal side to theproximal side. Then, when the cylindrical member is fixed by threads 80at appropriate positions, the positions of the balloons 66 a, 66 b and66 c are regulated. At this point, the outside diameters of the first tothird balloons 66 a, 66 b and 66 c can also be about the same when theballoons 66 a, 66 b and 66 c are in a deflated state. In this case, thefirst to third balloons 66 a, 66 b and 66 c are inflated when thecross-sectional areas of the first to third balloon communication holes68 a, 68 b and 68 c are the same. Then, the first balloon 66 a isinflated into the largest size and the second balloon 66 b is inflatedinto the second largest size because the first balloon 66 a is formedthinner than the second and third 66 b and 66 c and because the secondballoon 66 b is formed thinner than the third balloon 66 c. The thirdballoon 66 c is formed at the largest thickness and is thereforeinflated less.

Next, a fourth embodiment will be described using FIGS. 8A and 8B. Thisembodiment is a modification of the first embodiment, so that the samesigns are assigned to the same members as those described in the firstembodiment, and these members are not described in detail.

As shown in FIG. 8B, each of first to third balloons 66 a, 66 b and 66 cincludes a pair of bags 82 a and a pair of bands 82 b.

As shown in FIG. 8A, first to fourth grooves 84 a, 84 b, 84 c and 84 dare formed in the outer peripheral surface of a main body 62. The lengthL₁ between the first and second grooves 84 a and 84 b is formed to belarger than the length L₂ between the second and third grooves 84 b and84 c. The length L₂ between the second and third grooves 84 b and 84 cis formed to be larger than the length L₃ between the third and fourthgrooves 84 c and 84 d. In this case, the first balloon 66 a is formedthinner than the second balloon 66 b, and the second balloon 66 b isformed thinner than the third balloon 66 c.

Therefore, the times for inflating the first to third balloons 66 a, 66b and 66 c can be about the same. Then, it is possible to prevent, forexample, any one of the first to third balloons 66 a, 66 b and 66 c frombeing in an overpressurized state or a low pressure state.

Next, a modification of the fourth embodiment will be described usingFIG. 8C.

Among the grooves 84 a, 84 b, 84 c and 84 d shown in FIG. 8A, the secondgroove 84 b is used in common by the proximal side of the first balloon66 a and the distal side of the second balloon 66 b. The third groove 84c is used in common by the proximal side of the second balloon and thedistal side of the third balloon 66 c.

Conversely, grooves 92 a, 92 b, 94 a, 94 b, 96 a and 96 b shown in FIG.8C are separately provided. In this case, the positions of the balloons66 a, 66 b and 66 c can be suitably set. That is, the distance betweenthe balloons 66 a, 66 b and 66 c can be suitably set.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1. An endoscopic insertion aid comprising: a tube member which allows aninsertion section of an endoscope to be inserted therethrough and whichguides the longitudinal movement of the insertion section; a pipelinewhich is provided in the tube member and which communicates with asupply/discharge unit to supply a fluid to the distal end of the tubemember or discharge the fluid from the distal end of the tube member; aplurality of balloons which are disposed at the distal end of the tubemember longitudinally along the tube member and which communicate withthe pipeline and which inflate/deflate in accordance with thesupply/discharge of the fluid via the pipeline; and a regulatorconfigured to regulate so that a balloon disposed on the distal side ofthe tube member is inflated to have an outside diameter larger than thatof a balloon disposed closer to the proximal side of the tube memberwhen the plurality of balloons are inflated, wherein the regulator isarranged so that the length from the distal end to proximal end of theballoon disposed on the distal side of the tube member is larger thanthe length from the distal end to proximal end of the balloon closer tothe proximal side of the tube member.
 2. The endoscopic insertion aidaccording to claim 1, wherein the regulator is arranged so that the samematerial is used for the plurality of balloons and so that the thicknessof the balloon disposed on the distal side of the tube member is smallerthan the thickness of the balloon disposed closer to the proximal sideof the tube member.
 3. The endoscopic insertion aid according to claim1, wherein the balloon disposed on the distal side among the pluralityof balloons is formed of a material having an expansion rate higher thanthat of the balloon disposed closer to the proximal side of the tubemember.
 4. The endoscopic insertion aid according to claim 1, whereinthe pipeline includes: a connection pipeline connected to thesupply/discharge unit which supplies/discharges the fluid to/from theplurality of balloons; and a plurality of balloon communicationpipelines which branch from the connection pipeline to communicate withthe plurality of balloons and which supply/discharge the fluid to/fromthe plurality of balloons, the balloon communication pipelinecommunicating with the balloon disposed on the distal side of the tubemember among the balloon communication pipelines being less resistant tothe fluid than the balloon communication pipeline communicating with theballoon disposed closer to the proximal side of the tube member.
 5. Theendoscopic insertion aid according to claim 1, wherein thecross-sectional area of the balloon communication pipeline communicatingwith the balloon disposed on the distal side of the tube member amongthe balloon communication pipelines is larger than the cross-sectionalarea of the balloon communication pipeline communicating with theballoon closer to the proximal side of the tube member.
 6. An endoscopicinsertion aid comprising: a tube member which allows an insertionsection of an endoscope to be inserted therethrough and which guides thelongitudinal movement of the insertion section; a pipeline which isprovided in the tube member and which communicates with asupply/discharge unit to supply a fluid to the distal end of the tubemember or discharge the fluid from the distal end of the tube member; aplurality of balloons which are disposed at the distal end of the tubemember longitudinally along the tube member and which communicate withthe pipeline and which inflate/deflate in accordance with thesupply/discharge of the fluid via the pipeline; and regulating means forregulating so that the balloon disposed on the distal side of the tubemember is inflated to have an outside diameter larger than that of theballoon disposed closer to the proximal side of the tube member when theplurality of balloons are inflated, wherein the regulating means arearranged so that the same material is used for the plurality of balloonsand so that the thickness of the balloon disposed on the distal side ofthe tube member is smaller than the thickness of the balloon disposedcloser to the proximal side of the tube member.
 7. The endoscopicinsertion aid according to claim 6, wherein the balloon disposed on thedistal side among the plurality of balloons is formed of a materialhaving an expansion rate higher than that of the balloon disposed closerto the proximal side of the tube member than the balloon disposed on thedistal side.
 8. The endoscopic insertion aid according to claim 6,wherein the pipeline includes: a connection pipeline connected to thesupply/discharge unit which supplies/discharges the fluid to/from theplurality of balloons; and a plurality of balloon communicationpipelines which branch from the connection pipeline to communicate withthe plurality of balloons and which supply/discharge the fluid to/fromthe plurality of balloons, the balloon communication pipelinecommunicating with the balloon disposed on the distal side of the tubemember among the balloon communication pipelines being less resistant tothe fluid than the balloon communication pipeline communicating with theballoon disposed closer to the proximal side of the tube member.
 9. Theendoscopic insertion aid according to claim 6, wherein thecross-sectional area of the balloon communication pipeline communicatingwith the balloon disposed on the distal side of the tube member amongthe balloon communication pipelines is larger than the cross-sectionalarea of the balloon communication pipeline communicating with theballoon closer to the proximal side of the tube member.